Pliers-type hand tools with toggle-locking lever link mechanisms are generally known as toggle wrenches or locking pliers. These conventional tools usually comprise a fixed handle integral with a fixed jaw member and a movable jaw pivotably mounted on the fixed handle, a movable handle pivotably mounted on the movable jaw and a lever link pivotably mounted on the movable handle and extending to an adjustable point inside a channel in the fixed handle. This four-pivot mechanism is known as a toggle linkage. Conventionally a release lever for the toggle lock is pivotably mounted in the channel of the movable lever.
Certain patents which describe toggle locking hand tools are as follows:
______________________________________ Inventor U.S. Pat. No. Date of Issue ______________________________________ W. Petersen 1,489,458 Apr. 18, 1924 W. Petersen 2,201,918 May 21, 1940 W. Petersen 2,280,005 Apr. 14, 1942 Borchers 2,299,454 Oct. 20, 1942 Toernberg 2,341,489 Feb. 8, 1944 W. Petersen 2,417,013 Mar. 4, 1947 C. Petersen 2,563,267 Aug. 7, 1951 C. Petersen 2,590,031 Mar. 18, 1952 W. Petersen 2,711,663 Jun. 28, 1955 W. Petersen 2,853,910 Sept. 30, 1958 Hostetter Re. 26,280 Jan. 7, 1964/ Oct. 17, 1967 C. Petersen et al 3,192,804 Jul. 6, 1965 Schroeder 3,585,704 Jun. 22, 1971 Marasco 3,590,669 Jul. 6, 1971 Baldwin 3,600,986 Aug. 24, 1971 C. Petersen 4,541,312 Sept. 17, 1985 C. Petersen 4,546,680 Oct. 15, 1985 ______________________________________
Conventional locking hand tools may have jaws in the form of C-clamps, as in U.S. Pat. No. 2,641,149; in the form of chain clamps as in U.S. Pat. No. 3,192,804; in the form of long nose pliers as in U.S. Pat. Nos. 4,541,312 and 4,546,680; in the form of a straight jaw as in U.S. Pat. Nos. 2,201,918 and 2,280,005; in the form of curved jaws as in U.S. Pat. Nos. 2,563,267 and 2,853,910; in the form of a wire cutter as in U.S. Pat. No. 2,590,031; and in the form of an involute jaw as in U.S. Pat. No. 2,563,267. Locking hole punches are also known.
The novel mechanism of the present invention may be applied to the types of locking hand tools listed above or any other type of locking hand tool. All these tools have the basic purpose of seizing a workpiece and holding it firmly, when appropriately adjusted, accuated by the locking action of compressing the movable handle and the fixed handle. A release lever is provided to release the toggle-locking action in all of these hand tools.
U.S. Pat. No. 4,553,305 discloses a pipefitter's scribing and spacing tool with a series of complex static adjustments.
U.S. Pat. No. 4,483,059 shows a clamping and spacing tool with a pair of clamping jaws and shims which may be manipulated to provide a gap.
U.S. Pat. No. 4,344,215 discloses a pipefitter's tool with a jaw controlled by the movable handle and a U-shaped fixed jaw adjustable with bolts.
U.S. Pat. No. 4,306,345 discloses a pipefitter's tool with an internal fitting adjustable with shims and bolts.
U.S. Pat. No. 4,083,548 discloses an adjustable clamp in the form of two jaws mounted on a common bar.
U.S. Pat. No. 3,836,136 shows a racheted frame member bearing a clamp pad and a pivotably mounted clamp arm.
U.S. Pat. No. 3,241,410 discloses an adjustable racheted jaw on a racheted movable extension bar.
U.S. Pat. No. 3,092,378 discloses a C-clamp parallel to a main frame.
All eight of the preceding patents in the prior art have some type of toggle-locking mechanism.